Trimming device for embroidery machines



- March. 8,1921 1,620,378

, A. MISTRETTA TRIMMING DEVICE FOR EMBROIDERY MACHINES Filed Feb. 19. 1926 anomtgz 47mm; Adm/4:

Patented Mar. 8, 1927.

UNITED STATES 1,620,378 PATENT OFFICE.

ANTONIO MISTRETTA, OF NEW' YORK, N. Y.

TBIMMING DEVICE FOR EMBROIDE RY MACHINES.

Application filed February This invention relates to improvements in trimming attachments for embroidery sewing machines which are especially adapted for use in connection with machines of the Bonnaz type for producing appliqu embroidery; and its primary object is to provide certain improvements in the construction of the cutting device proper in order to improve and facilitate its operation, said cutting device being in the nature of a scissor-like implement of the type described and claimed by me in another patent application, entitled Trimming attachment for embroidery machines filed October 3rd, 1925, Serial No. 60,263.

Another object is to provide a cutting device of the character mentioned, which owing to a special arrangement of its blades will not interfere with or hamper the feeding of the cloth while the work is progressm (bther objects and advantages of the present invention will more fully appear as the description proceeds and will be set forth and claimed in the appended claims.

The invention relates to improvements in a mechanically operated cutting device which is capable of being turned about its axis in any direction required for following a pattern or outline, together with the needle bar which is capable of such movements under the control of the operator. The device is particularly designed for cutting out figures from fabrics parallel to a stitch which follows a certain predetermined outline through operations by which the cutting and stitching are effected simultaneously through the cooperation of various elements of which the device is composed.

By applique or Bonnaz embroidery is meant that kind of work where a piece or panel of decorative fabric is attached to a piece of fabric by means of a stitch which follows a certain predetermined outline representing some object or flower or animal, or other decorative motif or design.

Afterthe panel or applique work proper has become attached to the base fabric by means of the stitching, the same is trimmed all around the stitching leaving a certain margin, so that due to the difference between the materials of which the panel part and the base fabric are respectively composed, many novel and artistic effects may be obtaine 19, 1926. Serial No. 89,465.

The work is generally carried out in two distinct steps, the first-step being the stitchmg according to the design which may have been previously printed on the panel part and the other step being the trimming of the same which is generally performed by hand by means of ordinary scissors. This trimming operation is therefore, necessarily slow, due to the care which must be exerted 111 keeping the width of the margin uniform, and the result is not always perfect being largely dependent upon the ability of the operator to correctly gauge the width of the margin all around.

In my other application above referred to, I have described a device comprising a scissor-like device having a stationary blade and a movable blade, the movable blade bemg operated by a member which is attached to the needle bar and therefore follows both the axial and the angular movements of the needle bar. Said member transmits the axial movements of the needle bar to the movable blade by means of an articulated connection and the angular movements to the cutting device as a whole so that the shearing line is always set parallel to the stitching line.

In operating the said device, I have found it desirable to modify the same in its various details in order to obtain better results and more reliable'operation; and this invention more particularly concerns such changes as have proved of decided importance in improving the work that the device is intended to perform.

In describing the device in its present form, I will point out in detail the features whichhave thus been improved by referring to the previous arrangement.

In the annexed drawings Fig. 1 is a side view in elevation of my trimming attachment as applied to an embroidery machine;

Fig. 2 is"a front View in elevation of the same;

Fig. 3 is a rear view in elevation of the same;

Fig. 4 is a side view in elevation of the same with the needle bar in its lower position;

Fig. 5 is a detail plan sectional view I through line 55 of Fig. 1;

Fig. 6 is a detail plan sectional view through line 66 of Fig. 4; and

Fig. 7 is a detail plan sectional view through line 77 of Fig.1.

Referring. to Figs. 1, 2, and 8, 10 designates the needle bar which is represented at the highest point of its reciprocating travel, at which point its lower end 11 still projects beyond the lower end of needle bar casing 12. 13 designates a collar integral with a gear 14, which is an integral part of the equipment of the Cornely type of machine, which is restrained from axial movement by a retaining forked member 15 inserted in a groove 16, but which is free to rotatearound needle bar casing 12, upon which said collar isinserted. Said collar is therefore made use of for attaching the trimming attachment proper so as to render said attachment rotatable with the needle bar about its axis.

The trimming attachment proper consists of a stationary blade 17 which is carried by a vertical stem 18 depending from collar 13, being secured thereto by means of a clamping member 19, provided with lateral extene. sions 20, 21, attached to collar 13 by means of screws 22.

Clamping member 19 has a. longitudinal opening adapted to receivethe upper-end of stemlS, so thatsaid stem. may be. adjusted to and from the bed plate of the machine 23 21116.1 can then be. clamped in position. by means of screws 24.. This arrangement therefore renders the device adjustable for different thicknesses of cloth, the base material upon which the appliquwork is attached by stitching passing between the stationary blade 17 and the bed, plate 23.

The movable blade designated by 25 is pivotally mounted at 26 upon the lower end 27 of stem 18, with its cutting edge abutting against the cutting edge of blade 17 so that the two blades together form a scissor-like trimming contrivance adapted to trim the applique part-of the work quite close to the needle. 28=and at a uniform distance from the. stitch produced thereby.

The movable blade is caused to oscillate around its pivot by connecting. it with the needle bar, utilizing the reciprocating axial motion. of said needle bar. To. this end, an upwardly extending member 28 is secured to the lower portionvll of the needle bar by means-of a screw 29 or in any other suitable manner. The upper part 30 of said upwardly extending member, is connected to the upper end 31 of the movable blade by means of an articulated connection 32, so. that theupand. down motion of the needle bar will cause oscillating motion of said blade 25.

The upwardly-extending member28 has a vertical opening 83 through which passes stem 18,.which is thus maintained in its vertical position. Due to this it will be. observed that the angular movements of the needle bar, which are shared bymember 28 connected thereto, will be transmitted by said member 28 to stem 18 which is guided thereby, causing the collar 13 to participate in said angular movements. In order to insure a. sharp cutting action, I provide a spring 3 1 attached at 35 lo the upper part 30 of member 28,v said. spring forcing connection 32 outwardly and maintaining therefore blade 25 inclose adherence to blade 17, this action being comparable to the side pressure of one blade against the other, which is exertedby hand when using an ordinary pair ofscissors.

The arrangement described causes the cut ting device to be operated simultaneously with the needle and also causes the same to.

follow the angular displacements of the needle bar. Furthermore, by mounting the sta-. tionary blade so that the same is detached from thebed plate of the machine and vertically adjustable in relation thereto. it is possible to cut only one otthe fabrics employed in producing the workwhile the other fabric is unaffected by it. This is particularly important in connection with applique work since, as stated, only the applique or. panel part is trimmed while the base material is left untouched.

The material is fed to the needle by means of a presser foot 36 which is associated with the needle bar and which moves augularly therewith, said. presser foot moving inwardly each time a stitch is produced. in order to feed the fabric for the next stitch.

In Fig. 4 where the device is sliOWli in operation, being applied to the u'oduction of applique work,it will be observed that the presser foot is shown in its inwardposition after the feeding action. having started from the position shownin Fig. 1 where said foot is co-axial with the needle.

The pivotal connection between the two blades is somewhat to the rear of the needle, permitting of their cutting or operative portion being located exactly in correspondence with the needle itself, so that the cutting operation alwaystakes place at a point located at a line at right angle to the direction of the stitching at the point wvhei'ethe stitching takes place.

It will be observed thatthelower edge of the stationary blade is parallel to the upper surface of the bed plate otgthemachine. in order to provide a suitable :uljustable clearance space for the fabric passing therethrough. It will, also be observed that the stationary blade is very narrow and elongated, so that the cloth is only slightly raisedby the insertion ofsaid stationary blade between the base material-and the panel material.

Another-detail of importancein the construction of the stationary bladeis the bending tov one side of its outer end as shown at 37; this provides a transversal tract affordion lll)

ing a very efficient support for the fabric to be cut by the device, assisting the feeding action of the presser foot.

I will now describe in detail those points where important changes have been made as compared with the device described in my other patent application. In said previously described device, the stationary blade was the inner blade and the movable blade was the outer blade of the scissors, the stationary blade being integral with the stem. Due to the fact that while the cutting action takes place, the material is held down by the presser foot, which is of a relatively small diameter, the operation proceeded with some. diiiiculty because the rear part of the stationary blade and the stem were directly in the path of the fabric, requiring a stretching which was prevented by the action of the presser foot. This frequently caused tearing of edges and other difficulties, slowing down the work and requiring frequent stoppages and adjustments.

In the present case, the movable blade is the inner blade while the stationary blade is the outer blade, so that the inner part of the fabric which is cut and which is closely held by the base fabric due to the stitching, can freely run underneath the movable blade and no stretching effect is produced on said fabric. Due to this arrangement I have therefore been able to set the cutting device extremely close to the needle, and this is an advantage because the margin around the stitch should be as narrow as possible.

Another difference which will be observed, is in the mounting of the lower blade, which in the present case is mounted on but detachable from the stem. This lower blade as stated, is very narrow so as not to unduly stretch the cloth and therefore will not allow of many grindings; therefore, by making it detachable it isquite easy and iner pensive to set anew blade when the old one is worn out, without the necessity of chang-- ing the stem also.

The bending of the outer end of the station-ary blade as at 37 is also a new feature which greatly facilitates the work, since it positively prevents the possibility of the blade sliding out of position; it also assists in maintaining the fabric to be cut at right angle to the cutting edges, so that a sharp cutting action is obtained thereby.

By shifting the movable blade to the inner position, it becomes advantageous to insure a condition where its outer end does not reach the stationary or lower blade even when the movable blade is at the extreme end of its downward travel as shown in I i g. 4; this making it possible to connect the lon er end of connection 32 to theouter face of the movable blade by means of a pivot 38, without the possibility of interference by the lower or stationary blade.

In the device described, in my other application, close adherence of the movable to the stationary blade was obtained by a tension spring tending to force the movable blade inwardly; however, said tension spring was so placed that it was necessary to disconnect i in order to remove the attachment from the machine. In the present case, the movable blade being the inner blade, and the sta tionary blade the outer blade, the spring action should be such as to force the movable blade outwardly and therefore I have provided an unobtrusive and efi'ective spring 34 made of steel wire which is permanently attached to the device, and never needs to be touched. In this manner the attachment can be placed in position or removed therefrom, with greater ease and speed.

Another improvement which I have introduced is the manner of attaching stem 18 in position. In the former case, the stem was provided with a flat portion attached directly to collar 13 by means of screws inserted in longitudinal slots in order to permit axial adjustment of the stem. This necessitated the assembling of the flat portion and of the stem after insertion of the stem through guiding member 28, so that it became impossible to remove the stem again without disconnecting it from the flat portion; this coupled with the fact that the stationary blade was integral with the stem made the replacement of the stationary blade a dimcult and expensive operation. In the present case, the attachment is completely demountable, the stem being inserted both through member 28 and through its attaching collar 19; and by this arrangement a more solid and rigid construction is achieved where the stem is more easily adjustable and more easily held in position; furthermore, the device can be taken apart at any time and reassembled.

Another advantage deriving from this construction is that the removal of the attachment from the machine does not destroy the axial adj ustmentof the stem, since when part 19 is once more set in position, the st..- tionary blade automatically resumes its former position. VVhe-n the stem itself is directly attached to collar 13, the resetting of the attachment entails the necessity of once more adjusting the position of the stationary blade and this usually requires time and care.

\Vith the improvements set forth, the device has been rendered thoroughly practical and effective producing a neat and sharply cut margin of a very narrow width. The device does not interfere in the least with the ordinary operation of the machine which can be run at the usual speed.

I claim:

1. In a machine of the character specified, the combination with a needle bar capable of axial'reciprocating motion and capable of angular movement about its own axis, an axially stationary member coaxial therewith and adapted to rotate therewith, and a stationary blade mounted on said member, of a movable blade hinged at the inner side of said stationary blade, means associated with said needlebar adapted to cause motion of said movable blade, and means connecting said movable blade to said associated means the outer end of said movable blade being positioned so that it will not cross the stationary blade during its movement, permitting said connecting means to project transversely of the stationary blade.

2. In a machine of the character specified, the combination with a needle bar capable of axial reciprocating motion and capable of angular movement about its own axis and an axially stationary member coaxial therewith and adapted to rotate therewith, of a stem mounted on said member, a stationary blade detachably mounted on said stem, a movable blade hinged thereto at the inner side thereof, and means asiociated with said needle bar causing oscillating motion of said movable blade.

3. In a machine of the character specified, the combination with a needle bar capable of axial reciprocating motion and capable of angular movement about its own axis and an axially stationary member coaxial therewith and adapted to rotate therewith, of a stem mounted on said member, a stationary blade having its outer end bent transversely of its cutting edge detachably mounted on said stem, a movable blade hinged at the inner side thereof, and means associated with said needle bar causing oscillating motion of said movable blade.

4. In a machine of the character specified, the combination with a needle bar capable of axial reciprocating motion and capable of angular movement about its own axis and an axially stationary member coaxial therewith and adapted to rotate therewith, of acarrier mounted on said member, a stem mounted on said carrier axially adjustable in relation thereto, a stationary blade detachably mounted on said stem, a movable blade hinged at the inner side thereof, and means associated with said needle bar, causing oscillating motion of said movable blade.

5. In a machine of the character specified, the combination with a needle bar capable of axialreciprocating motion and capable of angular movement about its ownaxis and an axially stationary member coaxial therewith and adapted to rotate therewith, of a carrier mounted on said member, an axially adjustable stem mounted on said carrier, a stationary blade having its outer end bent transversely of its cutting edge, detachably mounted on said stem, a movable blade hinged at the inner side thereof, means associated with said needle bar adapted to cause oscillating motion of said movable blade, means connecting said movable blade to said associated means, said movable blade having its outer end positioned so that it will not cross the stationary blade during its movement, permitting said connecting means to project transversely of said stationary blade, and a spring tending to force said movable blade outwardly in close adherence to said stationary blade.

6. In a machine of the character specified, the combination with a needle bar capable of axial reciprocating,motion and capable of angular movement about its own axis and an axially stationary member-coaxial therewith and adapted to rotate therewith, of a carrier detachably mounted on said member, an axially adjustable stem mounted on said carrier, a stationary blade having its outer end bent transversely of its cutting edge-detachably mounted on said stem, a movable blade hinged at the inner side thereof, means associated with said needle barand detachable therefrom adapted to cause oscillating motion of said movable blade, means connecting said movable blade to said associated means, said movable blade having, its outer end positioned so that it will not cross the stationary blade during its movement, permitting said connecting, means to project transversely of said stationary blade, and a spring tendingtoforce said movable blade outwardly in close adherence to said stationary blade.

ANTONIO MISTRETTA. 

